Cryogenic liquid storage vessel



Sept. Z7, 1966 T. E. HOFFMAN ET AL CRYOGENIC LIQUID STORAGE VESSEL 3Sheets-Sheet l Filed June 14, 1965 Thomas E. Hoffman Wolter H. HoganINVENTORS Robert M. Lucas BY Raymond W. Moore,Jr.

Attgxney Sept. 27, 1966 T. E. HOFFMAN ET AL CRYOGENIC LIQUID STORAGEVESSEL Filed June 14, 1965 5 Sheets-Sheet 2 Ullmlllll L.

Fig.

Thomas E. Hoffman Wolrer H. Hogan Roberr Nl. Luces INVENTORS Raymond W.Moore, Jr.

Attorney Sept 27, 1966 T E* HQFFMAN ET AL `.3,274,788

CRYOGENIG LIQUID STORAGE VESSEL 5 Sheets-Sheet 5 Filed June 14, 1965Hoffman INVENTORS Thomos E. Wolter H. Hogan Roberll IVI. Lucas BYRaymond W. Moore,Jr.

AT orney United States Patent O 3,274,788 CRYOGENIC LIQUID STORAGEVESSEL Thomas E. Hoffman, Marblehead, Walter H. Hogan, Wayland, RobertM. Lucas, Melrose, and Raymond W.

Moore, Jr., Brookline, Mass., assignors to Arthur D.

Little, inc., Cambridge, Mass., a corporation of Massachusetts FiledJune 14, 1965, Ser. No. 463,792 15 Claims. (Cl. 62-45) This inventionrelates to a cryogenic storage Vessel and more particularly to aDewar-type vessel `for storing cryo- `genic lluids.

In the hand-ling and storing of cryogenic lluids, it is of coursenecessary to provide vessels which exhibit a minimum heat leak from thesurrrounding atmosphere into the cryogenic lluid which is containedtherein. Any undue amount of heat leak causes excess boil-off and henceloss of the cryogenic lluid. A number of -vessels have been built whichmay he referred `to as the Dewar-type, le., the type which basicallyconsists of an inner and outer vessel having the spacing between the twovessels sealed and evacuated. Many of these vessels are in use today anda variety of designs and constructions are available. However, becauseof the necessity for supporting the innner vessel lwith a support systemthat represents a minimum heat transfer path from the outer to the innervessel, Imost of the Dewar-type vessels now available are notparticularly rugged in construction. This means that these vesselscannot `be readily handled and transported without the exercise ofconsiderable care. Moreover, most of these vessels have fairly lowcapacities, e.g., -50 liters. It would therefore be desirable to have aDewar -storage vessel which is rugged, can withstand a considerableamount of handling, and can be fabricated in sizes from small up toextremely large, e.g., 3,000 liters.

It is therefore a primary object of this invention to provide animproved Dewar-type cryogenic storage vessel. It is another object `ofthis invention to provide such a storage vessel which is relativelyrugged and highly eflicient in that the boil-olf rate of cryogenicliquid stored therein is maintained at a minimum. It is yet anotherobject of this invention to provide a cryogenic storage vessel of thecharacter described which incorporates a unique lateral support system.It is a further object to provide such a vessel which does not requirean externally supplied coolant fluid. It is yet another object of thisinvention to provide a cryogenic storage vessel which may be constructedin a wide range of volumes and may be made to contain extremely largequantities of a cryogenic liquid. `It is still a further object of thisinvention to provide such a storage vessel which is so designed as tomake is particularly suitable for use as a vessel in which the cryogeniclluid is liquefied directly. Other objects of the invention will in partbe obvious and will in part be apparent hereinafter.

The invention accordingly comprises the features of construction,combination of elements and arrangement of parts which will beexemplified in the constructions hereinafter set forth, and the scope ofthe invention will 4be indicated in the claims.

lFor a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings in which FIG. 1 is alongitudinal cross-section of the cryogenic storage vessel of thisinvention;

vFIG. 2 is a cross-sectional detail of the bottom lateral support systemof the storage vessel;

iFIG. 3 is a cross-section taken along lines 3-3 of FIG. 2 showing asection of the bottom support system;

c ICC FIG. 4 is a cross-section taken through the lateral support bands;

IFIG. S is a cross-sectional detail of the upper lateral support system;

IFICl. 6 is a fragmentary cross-section of a portion of the insulationused;

FIG. 7 is a side elevational view, partly cut away, of the top of thestorage vessel;

FIG. -8 is a top plan view of the upper part of the stora'ge vessel; and

IFIG. 9 is a diagram of the alternative ow paths of the vented gas.

In keeping with the more or 'less basic Dewar design, there is providedin the cryogenic vessel of this invention an inner and outer vesselhaving the space between evacuated. Within this evacuated space is aradiation shield which is cooled hy boiled off vapor from the innnervessel, the cooling being extended to include the neck of the innervessel over certain selected areas. IInsulation is wrapped around theradiation shield and additional glass wool insulation is supplied aroundthe neck. The entire weight of the inner vessel, the radiation shieldand the insulation is supported through the neck and hence at the -topof the vessel. All of the lateral support Within the vessel for theinner vessel and the radiation shield is .provided by a unique type ofsupport system positioned at the bottom and top of the Dewar.

Turning now to FIG. 1 the general assembly of the cryogenic storagevessel of this invention may be seen. There is provided an inner vessel10 which contains the cryogenic liquid |11. IEntirely surrounding theinner vessel 10 is an outer vessel A12 which delines with the innervessel a fluid-tight, evacuatable space 13. Within this space andsurrounding the inner vessel is a cooled radiation shield 15 and aroundthe radiation shield is wrapped insulation 16 which conforms essentiallyto the configuration of the radiation shield. yAs will be -seen in FIG.5 the preferred form of the insulation is a structure which consists ofalternating coarse mesh l17 and aluminum foil 18, assembled to form amultilayered insulation in accordance lwith the teaching of -U.S. Patent3,152,033. The mesh is preferably formed of ber glassl coated with apolyvinyl resin from which at least some, and preferably all, of theplasticizer for the resin had been leached with a solvent such` asheptane. leaching out of thel resin plasticizer materially reduces oreliminates outgassing; but the resin still retains a sufficient degreeof thermoplasticity to make it heat weldable so that the insulation inbeing wrapped around the top and bottom of the radiation shield can bepleated to permanently conform to its con-figuration. The low thermalconductivity mesh furnishes spacing means `-for the multiple aluminumradiation shields. It is preferable to use about 30 layers of mesh andaluminum. However, more or less may be ernployed. The bottom of theouter vessel under this insulation is lilled with glass wool |14.

Returning now to FIG. 1, it will .be seen that a neck 19, preferably offairly large diameter, communicates between the interior of the innervessel and whatever connections are desired to be made with it as willbe described below. Neck 19 delines a relatively large diameter inlet 20into which an external Joule-Thomson valve with its attendant heattransfer passages may be inserted, thus making it possible to liquefygases, including helium, directly into the storage vessel. An externalJoule-Thomson lvalve suitable for insertion through neck passage 20 intothe inner vessel is described in a copending patent application SerialNo. 307,073, now Patent Number 3,201,947, led in the names of Arthur H.Post and Milton H. Streeter and assigned to .the same assignee as thepresent application.

The entire cryogenic storage vessel is preferably permanently mounted ona support system which in FIG. l is seen to comprise horizontal supports21 (of which there are four) and vertical supports 22.

The inner vessel is conveniently formed in three sections, namely acentral cylindrical section 23, an upper domed section 24, which isjoined to the cylindrical section by means of welding and -an inner band25, and a lower rounded section 26, joined to the cylindrical section 23through a welding and a similar inner band 27. The inner vessel, as Wellas the radiation shield, is supported by a lower support systemgenerally indicated by the numeral 30 in FIG. l. This lower supportsystem is shown in detail in FIG. 2 and will be described subsequently.Positioned below a central portion of the bottom of the inner vesselsection 26 is a wide annular dish 31. The spacing between this dish 31and the external wall of the inner vessel section 26 is filled withabsorbent material 32 such as activated charcoal. It will be appreciatedthat in this position the absorbent is maintained at a temperature whichapproximates that of the cryogenic fluid thus providing `an efficientcold trap. The lower support system 30 has attached to it three bands 33of low conductivity which are anchored to a support 34, This portion ofthe bottom lateral support system is also shown in detail in FIG. 2 andwill be described subsequently in connection with the discussion of thatfigure.

The radiation shield is preferably formed of three sections comprising athin central Icylindrical section 35, a thicker conically shaped topsection 36 and a thicker dish-shaped bottom section 37. This radiationshield is cooled by vapor from the inner vessel. This vapor accumulatesabove the liquid iin area 39 and is removed through coil 40 which, itwill be seen, is wound first around the vbottom of the neck 19 nearwhere it joins the inner vessel, then once around the radiation shield.In being wrapped around the radiation shield this vapor coolant tubing40 passes through top opening 41 to the outer surface of the shield,then through bottom opening 42 to form physical contact around aboutone-half of the inner surface of the section 37, then again out throughbottom opening 43 to physically contact the outer surface of centralsection 35 and top section 36 on the opposite side. The heat transferpath is, of course, through the walls of the tubing 40 from the walls ofthe radiation shield with which it makes physical contact. Tubing 40 isthen returned to the interior of the radiation shield through opening44, passes through a collar 45 which is positioned around the neck 19,and then is Wound :about the upper section of the neck so that itestablishes thermal contact with the neck at a number of locations shownin FIG. 3 to be in three places-47, 48 and 49. Tubing 40 then passesthrough a sealing member 46 to be connected to a T joint as describedwith reference to FIGS. 7-9.

The outer vessel, like the inner Vessel, is formed of three sectionsnamely a central section 50 which is attached to the upper dome section51 by an internally located joining angle ring 52 and to the lowerdished section 53 through another internally located joining ring 54.All of these sections are welded and are of course fluid-tight. In thebottom section 53 of the outer vessel there is a bottom plug 56 and asuitable joining conduit 57 for :attachment to an evacuation line. Thisconduit is sealed with a suitable plug 58. The outer vessel has an outerneck 60 which is sealed by plug 61 and over which an instrument assemblybox fits as shown in FIG. 7.

Located around the upper section of the outer vessel are a series ofears 62 which are used for lifting the storage vessel. The Dewar mayalso have longitudinal bar handles 63 (FIG. 7 shows one of these) whichare affixed to the horizontal supports 21 and to the upper section ofthe outer vessel. These are, of course, optional and any suitable meansfor handling the vessel may be used,

The neck which extends from the inner vessel and which, as previouslystated, supports the weight of the inner vessel, the radiation shieldand the insulation, is joined to the inner vessel through a series ofannular bushings 65 and 66 and a collar 67. It is joined to theradiation shield through collar 45 and a suitable bushing 68 (see FIG.5) and to the plug 61 through the bushing 69. Around that portion of theneck which extends above the radiation shield there is placed a sleeve72 which defines an annular space 73 with the neck. This is in fluidcommunication with the main evacuated space 13 through a right-angletubing member 74 which opens into a narrow -passageway 75 definedbetween the internal wall of the outer vessel and glass wool packing 76which is retained within a screening 77.

As in the case of the bottom portion of the vessel, the upper portion islaterally supported through the radiation shield by means of a lowthermal conductivity band 80 fastened to an anchoring system 81, thislateral support system being shown in detail in FIG. 5.

Turning noW to FIGS. 2 and 3 the bottom lateral support system may bedescribed in detail. -In these figures like numbers refer to likeelements shown in FIG. 1. At the center of the bottom section 26 of theinner vessel there is placed a sleeve which makes a fluid-tight sealwith this bottom section and which extends up into the inner vessel andthe cryogenic fluid stored therein. A sleeve 85 is attached to thebottom section 26 through an annular ring 86 and is sealed on the bottomby a plug 87 which is integral with a vertical downwardly extending maininner vessel lateral support stud 88. Surrounding this lateral supportstud 88 is a support stud tubing 90l which at its upper end is integralwith a relatively thick flange 91. On the outer or bottom surface of theflange 91 the radiation shielding bottom section 37 is aixed through useof an annular ring 92. The support stud tubing is closed with an end cap93 which can be removed for insertion of portions of the support system,and serves as a radiation barrier. Around the inner wall of the tubing90 are three lands 95 (shown in FIG. 3) which are in position t-ocontact a Pyrex glass ball 96. The lateral support stud 88 has asextensions three fingers 89 on which are located lands 94 whichalternate in position with lands 95. Although FIGS. 2 and 3 show the useof three lands 94 and three lands 95, it is within the scope of thisinvention to use more than three -of each. The lands in each set shouldbe equally spaced around the circumference of the ball and those of loneset yshould alternate with those of the other set. Lands 94 providecontacting surfaces 100; while lands 95 provide contacting surfaces 101.The ball 96, which rests upon a ball support 97, has a circumferencewhich is just slightly less than the circumference defined by thesurfaces 100 and 101 of the lands. This means that at any one time, thesurface of ball 96 makes contact with less than allot the surfaces ofthe lands. For example in FIG. 3, which illustrates the use of a totalof 6 lands, ball 96 is seen to contact only a single land 94 and -asingle land 95. This continuously minimizes the amount of contactingsurfaces and hence any heat leaks. Ball support 97 has associated withit an encircling ring 98 which serves to tie together fingers 89 so thatany radial loading put on one of the fingers and its -associated land.by the ball is also transmitted to the other fingers. Through a snapring 99 the ball support is positioned and held to the three fingers ofthe lateral support stud 88.

It will be seen that lands 94 are associated through stud `88, plug 87,sleeve 85 and collar 86 with the positioning yof the inner vessel;IWhile lands are associated through tubing 90, fiange 9l1 and ring 92with the positioning of the radiation shield. Ball 96 acting alternatelyon lands 94 and 95 maintains the inner vessel and radiation shield `inproper relative alignment and the three bands tl08 maint-ain the innerVessel and radiation shield in lateral alignment with the outer vessel,thus providing for all -of the lateral support.

yIt is normally desirable to be able continuously to monitor the liquidlevel within the storage vessel. There is therefore provided in thisstorage vessel a means for continuously determining the pressure atessentially the bottom of the liquid and above the liquid level. Theactual liquid level may then be determined since it is a function of thedifference of .these two pressures. There is therefore provided acapillary tubing 102 which communicates with the bottom of the liquid1.1 through a hole y103 drilled in the sleeve `85. This capillary 102continues up through the vessel and communicates 'with a pressuredilferential measuring device shown and described in connection withFIGS. 7 and `8.

FIGS. 2 and 4 also illustrate in detail the unique lateral supportsystem associated with the bottom section of the storage vessel. Aroundthe support stud tubing 90 is aixed an annular collar 105 which hasmachined in it t-hree recesses 106. Only one of these is shown in FIG.2, but it will be appreciated that they are spaced 120 apart and thusprovide for a balanced three-directional support for the inner vesseland the radiation shielding. A spool 107 passes through the recess 106and `around it is Wound a band, one-half of which is shown in FIG. 2.\FIG. 4 shows the entire band `108 in cross-section. This band 108 ispreferably formed of monolament fiber glass embedded in an epoxy resin.The other terminal for the band is anchored to the inner wall of theouter vessel through the support 34, as is shown in =FIG. 1. A U-shapedanchoring piece 109 has a pin `1.10 extending through it and the band108 passes around the pin. The band anchoring piece 109 is held to thesupport 34 through a bolt 112, nuts 113 and spherical alignment washer1v1-4, an arrangement which provides for band adjustments.

A mesh `1111 extends horizontally Within the outer vessel directly belowthemultiple-radiation lshield insulation '16 and around the bottom edgeof it. Glass wool insulation 14 is packed within the outer vessel belowthis mesh 111 and additional yglass wool 14a may be used to ll the spacebetween the insulation 16 and the upper surface of the mesh.

yThe lateral support system at the top of .the vessel is similar inconstruction to that usedfat ythe bottom, and, as in the case of thebottom lateral support, three bands are used. This top lateral supportsystem is shown in detail in FIG. 5. It Will be seen from thisfragmentary cross-sectional detail of FIG. 5 that the upper lateralsupport system is attached'to a bushing `68 through which a suitablebolt 120 is passed to attach the upper end of the upper section 36 ofthe radiation shield to the collar 45 which in turn is mounted on theneck '19. Attached to the .bushing -68 is an annular ring =121 which hasa recess A122 into which is fitted a pin 123. The ber glassepoxy band124 fits around this pin and a second pin 127 which is held in a yoke125 having a recess 126. The yoke 125 is in turn aixed to the peripheralattaching means generally indicated bythe numeral 81, through an anglepiece 130 which is welded to a support y13:1. `This Vattachment islikewise achieved through the use of a bolt y133, a nut 1'34 andspherical alignment washer i135 for providing adjustments.

Turning now to FIGS. 7-9, it will be seen how external connections areeffected with the inner vessel of the cryogenic storage vessel. Aninstrument assembly box 138 Vfitted with a fluid-tight sealing bushing139 fits over the upper end of .the neck 219 and sits on the top of theouter vessel. The tubing y40 which vents the cold vapor from the innervessel extends through this instrument box, and as will be seen in FIG.9 there is provided a choice for the path of the vented gases. This isdone through the use of a T-joint. The lirst alternative of gas dow,which is the one used while liquefaction is taking place within t-hestorage vessel, is through a valver140 which is in uid communicationwith a flow meter |142.

This How meter is preferably of the type which permits setting anindication of a desired gas iiow. By determining `the normal venting ofgas through this flow meter when the storage vessel contains a cryogenicliquid and is being used only for storage, a normal boil-off rate isnoted. The indicator of flow meter 142 is then set at this normalboil-01T rate to serve as aY basis for check-` ing, during Aliquefactionwithin the vessel, to determine whether there is a proper ow of gasthrough the vent tube to keep the radiation shield cold.

From the lio-w meter 142 the vented gas passes through a muffler 144 andthen by way of a suitable conduit (not shown) into the pressure circuitof a liquetier or other apparatus. The purpose of the mufer is to reduceor entirely eliminate the pulsations which may be present in thelow-pressure line leading to the compressor. Normally as a compressortakes in gas periodically it develops pulses, and transmission of suchpulses back int-o the storage vessel must be minimized because theyinterfere with the proper operation of dow meter 142 and set up unwantedthermal oscillations.

The other alternative path of .the vented gas from tubing 40 is directlyto the atmosphere in which case valve '140 is closed and the gas istaken to the atmosphere by way of a manual valve 146 and relief valve147. By maintaining .the flow of gas only outwardly, no moist air ispermitted to enter the system. This alternative route for the vented gasis used when the vessel is used only for storage and not liqueactiOn.

As pointed out in the description of FIG. 2, there is a small capillary102 which is open to the inner vessel and which communicates 'with adifferential pressure gage. This capillary 102 passes through the .topof the instrument assembly box and communicates with differentialpressure gage 15|1 as will be seen in FIGS. 7 and 8. Capillary 148,which communicates with the inner volume ofthe inner vessel through neck-19 and the T connector A154, leads into the differential pressure gage'151. By determining the difference in the pressures at the bottom ofthe liquid and at the .top of the inner vessel it is possible to readout directly the amount of liquid contained Within the inner vessel on asuitably calibrated gage.

:In order to provide suitable inlet connections into the inner vessel,there is provided a T connector |154 which slips 'down over the fit-tingbushing 139 of the instrument assembly box. This is shown in detail inFIG. 7. Two relief valves 156 and 157 are connected to the T connectorfor the purpose of providing alternative pressure release routes for gaswhich might accumulate in the inner vessel. A conduit 159 with asuitable 'fitting gland |160 is provided for inserti-on of a draw-offtube to remove cryogenic liquid from the storage vessel. In similarfashion a conduit 161 is provided with a gland connector 162 for makingsuitable connections with an external Joule- 'Ihomson va-lve assemblywhich is inserted into the storage vessel for |liquefaction within thevessel. It is, of course, possible to provide other connecting linesinto the storage vessel, as well as to close these off, but it should benoted that with the large diameter neck provided it is possible toinclude more than one such connection and to choose among a number ofconnections depending upon the use to which the storage vessel is put.An auxiliary T connector 163 is connected to the main T connector 154and provides for connecting capillary i148 .to the volume of the innervessel and also serves as a means to connect a service valve i164, thepurpose of which is to provide for pressurizing or evacuating the innervessel if this is desired. Finally there is also connecte-d to this Tconnector a pressure gage 165 which permits continuous monitoring of thegas pressure in the inner vessel.

It will be seen from the above description that the Dewar-type cryogenicstorage vessel of this invention provides a rugged device which can bemoved and handled without any undue care. The upper and lower lateralsupport systems assure lateral alignment of the cryogenic storage vesselat all times. The inner Vessel may conveniently be constructed ofstainless steel which is known to have excellent structural strength atthe very low temperatures at which it is maintained when a cryogenicliquid is contained therein. By providing a relatively large-diameterneck it is possible to make a number of different types of connectionsinto the interior of the vessel. Moreover, the thermal design of thevessel is such as to minimize heat leaks into any cryogenic liquidstored therein. At the same time it makes the most eicient use of thecold boiled-off vapor by cooling the bottom end of the neck, then theradiation shield and finally the top end of the neck. The ball supportsystem achieves maximum support with essentially minimum thermalcontact. Finally the cryogenic vessel of this invention is adaptable forconstruction in a wide range of sizes from relatively small to verylarge.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are eiciently attained andsince certain changes may be made in the above construction withoutdeparting from the scope of the invention it is intended that all mattercontained in the above description or shown in the accompanying drawingsshould be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of language, might be said to fall therebetween.

We claim:

1. In a cryogenic liquid storage vessel formed of an inner vessel havinga neck section, an outer vessel and an evacuated space therebetween inwhich is located radiation shield means, a lateral support system formedof (a) a bottom lateral support comprising in combination (l) avertically disposed stud afxed to the bottom of said inner vessel andhaving depending therefrom at least three equally spaced eX- tensionsforming curved contacting inner vessel lands,

(2) a sheath surrounding the bottom portion of said stud, aliixed tosaid radiation shield and having on its internal walls at least threecurved and equally spaced contacting lands in the same plane as saidinner vessel lands and alternating in position With said inner vessellands,

(3) a spacer body of low thermal conductivity positioned to contact thesurface of said lands, whereby said inner vessel and said radiationshield are maintained in relative alignment, and

(4) at least three, low thermal conductivity bands equally spacedconnecting said sheath and the internal wall of said outer vessel; and

(b) a top lateral support, comprising in combination (l) connector meansjoining said radiation shield means with said neck section of said innervessel, and

(2) at least three, low thermal conductivity bands equally spacedconnecting said connector means and the internal wall of said outervessel.

2. A cryogenic liquid storage vessel in accordance with claim 1 whereinsaid spacer body is a spherical glass ball.

3. A cryogenic liquid storage vessel in accordance with claim 1 whereinsaid extensions depending from said stud are held together at theirterminal end by a map ring whereby any radial loading put on oneextension and its associated inner vessel land is transmitted to the.other of said c2$ @1 1$.i0 11$.

4. A cryogenic liquid storage vessel in accordance with claim 1 whereineach of said bands is in the form of a continuous belt held at each endby horizontally disposed `end members, the position of said end-membersassociated with the internal wall of said outer vessel being adjustable.

5. A cryogenic liquid storage vessel in accordance with claim 1 whereinsaid bands are formed of monolament fiber glass embedded in an epoxyresin.

6. A cryogenic liquid storage vessel, comprising in combination (a) aninner vessel adapted to contain a cryogenic liquid and having a neck forcommunication with the interior thereof;

(b) an outer, fluid-tight vessel surrounding said inner vessel and aportion' of said neck and defining therewith an evacuatable space;

(c) a radiation shield around said inner vessel within said evacuatablespace and attached to said neck of said inner vessel through connectormeans;

(d) insulation wrapped around the outside of said radiation shield; and

(e) a lateral support system formed of (l) a bottom lateral supportcomprising (i) a vertically disposed stud afxed to the bottom of saidinner vessel and having depending therefrom at least three equallyspaced extensions forming curved contacting inner vessel lands,

(ii) a sheath surrounding the bottom portion of said stud, affixed tosaid radiation shield and having on its internal walls at least threecurved and equally spaced contacting lands in the same plane as saidinner vessel lands and alternating in position with said inner vessellands, v

(iii) a spacer body of low thermal conductivity positioned to contactthe surface of said lands, whereby said inner vessel and said radiationshield are maintained in relative alignment, and

(iv) at least three, low thermal conductivity bands equally spacedconnecting said sheath and the internal wall of said outer vessel; and

(2) a top lateral support comprising at least three, low thermalconductivity bands equally spaced connecting said connector means andthe internal wall of said outer vessel.

7. A cryogenic liquid storage vessel in accordance with claim 6 furthercharacterized by having vapor coolant tubing means adapted to withdrawcold vapor from within said inner Vessel and to cool in order, throughout-of-contact heat exchange, said neck near its juncture with saidinner vessel, said radiation shield, yand the upper portion of said neckenclosed within said outer vessel.

8. A Cryo-genie liquid storage vessel in accordance with claim 6 furthercharacterized by having additional insulation located between `the upperportion of said neck enclosed in said outer vessel and the internalw-all of said outer vessel and being spaced from said neck and saidinternal wall thereby to prevent the fluid isolation of any portion ofsaid evacuatable space.

9. A cryogenic liquid storage vessel in accordance with claim 6 furthercharacterized by having additional insulation lilling the bottom portionof said outer vessel and separated from said insulation Wrapped aroundsaid radiation shield by a coarse mesh member.

10. A cryogenic liquid storage vessel in accordance with claim 6 furthercharacterized by having la plate member maintained in spacedrelationship from the central portion of the external Wall ofthe bottomof said internal vessel and an adsorbent material filling the volumetherebetween.

11. A cryogenic liquid storage vessel in accordance with claim 6 whereinsaid insulation wrapped -around said radiation shield comprises amultiplicity of aluminum foil sheets maintained in spaced relationshipby a coarse netting formed of polyvinyl-coated glass fibers, at least aportion of the plasticizer of said polyvinyl coating having been removedby leaching with a solvent.

12. A cryogenic liquid storage vessel in accordance with claim 11wherein said insulation in being wrapped around said radiation shield isheat welded through said netting to permanently conform to ftheconliguration of said radiation shield.

13. A cryogenic liquid storage vessel, comprising in combination (a) aninner vessel adapted to contain a cryogenic liquid and having a neck forcommunication with the interior thereof;

(b) an outer, Huid-tight vessel surrounding said inner vessel and aportion of said neck and dening therewith an evacuatable space;

(c) a radiation shield around said inner vessel within said evacuatablespace and attached to said neck of said inner vessel through -connectormeans;

(d) vapor coolant tubing means adapted to withdraw cold vapor fromwithin said inner vessel and to cool in order, through out-of-contactheat exchange, said neck near its juncture with said inner Vessel, saidradiation shield, and the upper portion of said neck enclosed withinsaid outer vessel;

(e) insulation wrapped around the outside of said radiation shield;

(f) a lateral support system formed of 1) a bottom lateral supportcomprising (i) a vertically disposed stud affixed to the bottom of saidinner vessel and having depending therefrom at least three equallyspaced extensions forming curved contacting inner vessel lands,

(ii) a sheath surrounding the bottom portion of said stud, affixed tosaid radiation shield and having on its internal walls at least threecurved and equally spaced contacting lands in the same plane -as saidinner vessel lands and alternating in position with said inner vessellands,

(iii) a spacer body of low thermal conductivity positioned to contactthe surface of said lands, whereby said inner vessel and said radiationshield are maintained in relative alignment, `and 10 (iv) at leastthree, low thermal conductivity bands equally spaced connecting saidsheath and the internal wall of said outer vessel; and (2) a top lateralsupport comprising at least three, low thermal conductivity bandsequally spaced connecting .said connector means :and the internal wallof said outer vessel;

(g) a rst capillary tubing in Huid communication with the bottom levelof the cryogenic liquid in said inner vessel and extending externally ofsaid storage vessel;

(h) a second capillary tubing in fluid communication with the internalvolume of said inner vessel :above the upper level of said cryogenicliquid and extending externally of said storage vessel; and

(i) instrumentation and connecting assembly means adapted to form afluid-tight seal with the upper `opening `of said neck of said innervessel and arranged to provide fluid connections between externalconduits and said inner vessel, and fluid connections for said vaporcoolant tubing, said tirst capillary tubing and said second capillarytubing.

14. A cryogenic Iliquid storage Vessel in accordance with claim 13wherein said fluid connection for said vapor coolant tubing comprises aT-connecting means in fluid communication with valve-controlled firstand second alternative fluid paths; said rst Huid path including a fluidow meter and a muliler adapted for use when liquefaction of saidcryogenic liquid takes place within said inner vessel; and said secondflow path including one-way uid ow control means and a relief valve.

15. A cryogenic liquid storage vessel in accordance with claim 13wherein said fluid connections for said first and second capillary tubesterminate in a pressure differential measuring means, Ithereby providingthrough suitably calibrated gage an indication of the level of saidliquid in said inner vessel.

References Cited by the Examiner UNITED STATES PATENTS 2,528,780 11/1950 Preston 62-50 2,951,348 9/1960 Loveday et al. 62-50 3,133,422 5/1964 Paivanas et al. 62-50 3,134,237 5/ 1964 Canty et al. 62-50 FOREIGNPATENTS 662,356 4/1963 Canada. 662,411 4/ 1963 Canada.

LLOYD L. KING, Primary Examiner.

1. IN A CRYOGENIC LIQUID STORAGE VESSEL FORMED OF AN INNER VESSEL HAVINGA NECK SECTION, AN OUTER VESSEL AND AN EVACUATED SPACE THEREBETWEEN INWHICH IS LOCATED RADIATION SHIELD MEANS, A LATERAL SUPPORT SYSTEM FORMEDOF (A) A BOTTOM LATERAL SUPPORT COMPRISING IN COMBINATION (1) AVERTICALLY DISPOSED STUD AFFIXED TO THE BOTTOM OF SAID INNER VESSEL ANDHAVING DEPENDING THEREFROM AT LEAST THREE EQUALLY SPACED EXTENSIONSFORMING CURVED CONTACTING INNER VESSEL LANDS, (2) A SHEATH SURROUNDINGTHE BOTTOM PORTION OF SAID STUD, AFFIXED TO SAID RADIATION SHIELD ANDHAVING ON ITS INTERNAL WALLS AT LEAST THREE CURVED AND EQUALLY SPACEDCONTACTING LANDS IN THE SAME PLANE AS SAID INNER VESSEL LANDS ANDALTERNATING IN POSITION WITH SAID INNER VESSEL LANDS, (3) A SPACER BODYOF LOW THERMAL CONDUCTIVITY POSITIONED TO CONTACT THE SURFACE OF SAIDLANDS, WHEREBY SAID INNER VESSEL AND SAID RADIATION SHIELD AREMAINTAINED IN RELATIVE ALIGNMENT, AND (4) AT LEAST THEEE, LOW THERMALCONDUCTIVITY BANDS EQUALLY SPACED CONNECTING SAID SHEATH AND THEINTERNAL WALL OF SAID OUTER VESSEL; AND (B) A TOP LATERAL SUPPORT,COMPRISING IN COMBINATION (1) CONNECTOR MEANS JOINING SAID RADIATIONSHIELD MEANS WITH SAID NECK SECTION OF SAID INNER VESSEL, AND (2) ATLEAST THREE, LOW THERMAL CONDUCTIVITY BANDS EQUALLY SPACED CONNECTINGSAID CONNECTOR MEANS AND THE INTERNAL WALL OF SAID OUTER VESSEL.